From the New Latin hyoideus, sublingual, and ...stylium.

A type of articulation of the jaw apparatus with the cerebral skull in which the main maxillary bone in bony and the absolute majority of cartilaginous fish is connected to the skull only by ligaments and has a single articulation in the auditory region of the skull through a suspension, the hyomandibular muscle (hyomandibulare). The hyomandibular ensures mobility of the jaws and wide opening of the mouth. In sharks, the pendant is represented by one massive cartilage, in rayfishes it splits into two independent ossifications - the pendant itself (hyomandibulare) and a small connective bone (symplecticum).Hyostylum increases the mobility of the jaw apparatus, but does not provide sufficient strength. In fish with jaws of the crushing type, hyostylyis is usually replaced by amphistylyis or autostylyis.